Getting to Mars

Abstract

Mars launch opportunities happen about every 26 months, as Earth begins to approach Mars from behind on its faster inside track around the Sun. The earliest MSL could launch was November 25, 2011; any earlier, and it would arrive at Mars with too much speed for the entry, descent, and landing system to dissipate. The latest it could launch was December 18; any later, and the Atlas V 541 rocket wouldn’t have enough thrust to deliver the spacecraft to its rendezvous point with Mars.